An example of the above, disclosed in Patent Literatures 1 to 3 below, is the one constituted by combining a first member integrally attached to an inner member and a second member; the second member is integrally attached to an outer member and has a seal lip portion that is made of elastic material and elastically contacts the first member. Patent Literatures 1 to 3 disclose the sealing device in which the first member, i.e. a slinger, has a first cylindrical portion, a circular plate portion, and a second cylindrical portion. The first cylindrical portion is fitted to the inner member; the circular plate portion extends into an outer diametrical side from an end portion of the first cylindrical portion on an opposite side to the second member; and the second cylindrical portion extends in the same direction as the first cylindrical portion from an outer diametrical side end portion of the circular plate portion in the axial direction. The second member of the sealing device has a core member and the seal lip portion. The core member has a cylindrical portion that is fitted to the outer member, and a flange portion that extends from one end portion of the cylindrical portion into an inner diametrical side. The seal lip portion, made of elastic material, is fixed to the core member and elastically contacts the slinger. A labyrinth portion is formed between opposite faces of the second cylindrical portion of the first member and the second member.